Molten Chocolate Lava Cakes

Before you start

A lava cake is a rich chocolate batter baked hot and fast so the outside sets into a thin cake while the middle stays liquid. There is very little flour; the batter is mostly melted chocolate, butter and eggs whipped with sugar. The flowing center is simply underbaked batter, which is why the oven window is narrow and worth watching closely.

Quality chocolate matters because it makes up most of the flavor. Choose a bar of 60 to 70 percent bittersweet rather than chips, which contain stabilizers that resist melting smoothly. Butter and cocoa the ramekins thoroughly, since a cake that sticks will tear open when you invert it.

Ingredients

• 1 tbsp soft butter and unsweetened cocoa powder — for the ramekins
• 115 g (4 oz) bittersweet chocolate (60 to 70 percent) — chopped
• 115 g (½ cup) unsalted butter — cut into pieces
• 2 large eggs — room temperature
• 2 large egg yolks
• 50 g (¼ cup) granulated sugar
• ⅛ tsp fine salt
• 16 g (2 tbsp) all-purpose flour
• to serve powdered sugar, berries or vanilla ice cream

Method

1. Heat the oven to 220°C (425°F) with a rack in the middle. Brush the ramekins generously with soft butter, add a spoon of cocoa, tilt to coat and tap out the excess. Set them on a baking sheet.
2. Melt the chocolate and butter together over barely simmering water or in 20-second microwave bursts, stirring until smooth. Let cool for 5 minutes.
3. Beat the eggs, yolks, sugar and salt on high for about 4 minutes, until thick and pale and a ribbon holds on the surface for a moment.
4. Fold the warm chocolate into the eggs in two parts, then sift the flour over and fold just until no streaks remain.
5. Divide the batter evenly among the ramekins, filling them about three-quarters full.
6. Bake for 12 to 14 minutes, until the tops are puffed and set at the edges and the centers still wobble when you nudge the pan. The sides should look firm and pull very slightly from the dish.
7. Let the cakes stand for 1 minute. Run a thin knife around each, set a plate on top and invert. Wait 10 seconds, then lift the ramekin off. Dust with powdered sugar and serve at once.

Tips for success

• Bake one test cake first if you are serving guests. Ovens vary, and a 1-minute difference changes a molten middle to a fudgy one.
• Metal or thin ceramic ramekins bake faster than thick stoneware; start checking at 11 minutes in thin cups.
• Serve right away. The center keeps cooking from residual heat and firms within about 5 minutes.

Substitutions

All-purpose flour

Use 2 tbsp almond flour or 1 tbsp cornstarch for a gluten-free version. The edges are a little softer and more fragile when unmolding.

Bittersweet chocolate

Semisweet chocolate gives a sweeter, milder cake; cut the sugar to 35 g. Milk chocolate stays too soft to hold the walls.

Cocoa for the ramekins

Granulated sugar gives a lightly crisp crust and releases just as well.

Variations

Make-ahead lava cakes

Fill the ramekins, cover and refrigerate for up to 24 hours. Bake straight from the refrigerator, adding 2 to 3 minutes.

Peanut butter center

Drop 1 tsp of chilled peanut butter into the middle of each filled ramekin and push it just below the surface.

Troubleshooting

Cake collapsed when unmolded

It was underbaked. Bake another minute until the sides look clearly set, and let it rest for the full minute before inverting.

No molten center

It baked too long or the oven runs hot. Take it out while the top center still jiggles, and check the oven with a thermometer.

Cake stuck to the ramekin

The coating had gaps. Butter every bit of the inside, including the rim, and coat with cocoa or sugar.

Storage

Lava cakes are meant to be eaten immediately. Leftovers can be refrigerated, covered, for up to 2 days; they reheat in the microwave in about 20 seconds as a fudgy cake rather than a flowing one.

Safety notes

The liquid center does not reach 71°C (160°F), the temperature at which eggs are considered cooked. For young children, pregnant people, older adults or anyone with a weakened immune system, use pasteurized eggs or bake until the center is set. Contains egg, milk and wheat.